Monocoque jaw design

ABSTRACT

A jaw member for use with an electrosurgical forceps includes a support member having a first surface and a pair of depending sides which extend therefrom forming a generally U-shaped configuration. The free end of the sides each including a flange which extends outwardly therefrom which is designed to attach to an electrically conductive plate such that the plate bridge the two flanges to enclose the U-shaped support member to form a box-like skeleton having a cavity defined therein. An insulative material is disposed within the cavity and an insulative cover is disposed about a periphery of the box-like support skeleton to insulate surrounding tissue during activation of the conductive plate.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. application Ser. No.12/361,369, Jan. 28, 2009, which claims priority to, and the benefit of,U.S. Provisional Patent Application No. 61/030,771, filed on Feb. 22,2008, the entire contents of each of which are hereby incorporated byreference.

BACKGROUND

1. Technical Field

The present disclosure relates to an electrosurgical forceps and, moreparticularly, the present disclosure relates to a method ofmanufacturing jaw members for an end effector assembly for use witheither an endoscopic or open bipolar and/or monopolar electrosurgicalforceps.

2. Background of Related Art

Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue. As an alternative toopen forceps for use with open surgical procedures, many modern surgeonsuse endoscopes and endoscopic instruments for remotely accessing organsthrough smaller, puncture-like incisions. As a direct result thereof,patients tend to benefit from less scarring and reduced healing time.

Endoscopic instruments are inserted into the patient through a cannula,or port, which has been made with a trocar. Typical sizes for cannulasrange from three millimeters to twelve millimeters. Smaller cannulas areusually preferred, which, as can be appreciated, ultimately presents adesign challenge to instrument manufacturers who must find ways to makeendoscopic instruments that fit through the smaller cannulas.

Many endoscopic surgical procedures require cutting or ligating bloodvessels or vascular tissue. Due to the inherent spatial considerationsof the surgical cavity, surgeons often have difficulty suturing vesselsor performing other traditional methods of controlling bleeding, e.g.,clamping and/or tying-off transected blood vessels. By utilizing anendoscopic electrosurgical forceps, a surgeon can either cauterize,coagulate/desiccate and/or simply reduce or slow bleeding simply bycontrolling the intensity, frequency and duration of the electrosurgicalenergy applied through the jaw members to the tissue. Most small bloodvessels, i.e., in the range below two millimeters in diameter, can oftenbe closed using standard electrosurgical instruments and techniques.However, if a larger vessel is ligated, it may be necessary for thesurgeon to convert the endoscopic procedure into an open-surgicalprocedure and thereby abandon the benefits of endoscopic surgery.Alternatively, the surgeon can seal the larger vessel or tissue.

It is thought that the process of coagulating vessels is fundamentallydifferent than electrosurgical vessel sealing. For the purposes herein,“coagulation” is defined as a process of desiccating tissue wherein thetissue cells are ruptured and dried. “Vessel sealing” or “tissuesealing” is defined as the process of liquefying the collagen in thetissue so that it reforms into a fused mass. Coagulation of smallvessels is sufficient to permanently close them, while larger vesselsneed to be sealed to assure permanent closure.

A general issue with existing electrosurgical forceps is that the jawmembers are constructed to include a steel structural support member,which typically requires precise machining and assembly making the jawmember manufacturing process costly and time consuming.

SUMMARY

The present disclosure relates to a method for manufacturing a jawmember and includes the initial step of providing a conductive plate anda support member. The support member includes a flange extendingtherefrom (e.g., on the tip, around the perimeter, and/or along thelength, etc.). The method also includes the steps of: attaching theconductive plate to the flange to form a box-like support skeletonhaving a cavity defined therein; inserting a filler material into thecavity to maintain a rigid support and to add strength to the jaw memberas the conductive plate presses against the support member; and an outerinsulative cover disposed on an outer periphery of the box-like supportskeleton with an insulative cover. In embodiments the filler materialmay be insulative or conductive. The filler material and the insulativecover may be made from similar material and may include plastic, epoxy,polymer-based materials, resin, carbon fiber, gel and combinationsthereof.

In one embodiment, the step of attaching the conductive plate to thesupport member to form a box-like support skeleton includes at least oneof welding, soldering, gluing and mechanically engaging. In anotherembodiment, the support member may be stamped to form a substantiallyU-shaped configuration. In other embodiments, the support member mayhave any other suitable shape, for example, a substantially partialO-shaped configuration, or a substantially V-shaped configuration. Instill another embodiment, the conductive plate includes a knife slotdefined therein.

The present disclosure also relates to a method for manufacturing a jawmember and includes the steps of: providing a conductive plate and aU-shaped support member having flanges and which extend therefrom;attaching the conductive plate to the flanges along a length thereof toform a box-like support skeleton having a cavity defined therein;inserting an insulative material into the cavity to insulate and supportthe conductive plate against the U-shaped support member; and attachingan insulative cover to an outer periphery of the box-like supportskeleton to insulate tissue from the support structure.

The present disclosure also relates to a jaw member for use with anelectrosurgical forceps having a support member with a first surface anda pair of depending sides which extend therefrom forming a generallyU-shaped configuration. The free end of each side includes a flangewhich extends outwardly therefrom. A conductive plate connects to anelectrosurgical energy source and is welded to the support member tobridge the flanges and enclose the support member to form a box-likeskeleton having a cavity defined therein. An insulative material isdisposed within the cavity to provide structural support to theconductive plate and an insulative cover is disposed about a peripheryof the box-like support skeleton to insulate surrounding tissue duringactivation of the conductive plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a perspective view of a pistol-grip style endoscopic bipolarforceps having a housing, a shaft and an end effector assembly accordingto one embodiment of the present disclosure;

FIG. 1B is a perspective view of an in-line endoscopic bipolar forcepshaving a housing, a shaft and an end effector assembly according toanother embodiment of the present disclosure;

FIG. 2A is an enlarged, perspective view of the end effector assembly ofFIG. 1A;

FIG. 2B is an enlarged, side view of the end effector assembly of FIG.1A;

FIG. 3 is an enlarged, cross sectional view of a bipolar jaw memberaccording to one embodiment of the present disclosure;

FIG. 4 is an enlarged, cross sectional view of a bipolar jaw memberaccording to another embodiment of the present disclosure;

FIG. 5 is an enlarged, exploded view of the bipolar jaw member of FIG.3; and

FIG. 6 is a flow chart showing a method of manufacturing a jaw memberaccording to the present disclosure.

DETAILED DESCRIPTION

Embodiments of the presently disclosed electrosurgical instrument aredescribed in detail with reference to the drawing figures wherein likereference numerals identify similar or identical elements. As usedherein, the term “distal” refers to that portion which is further fromthe user while the term “proximal” refers to that portion which iscloser to the user or surgeon.

One embodiment of a forceps for use with the present disclosure includesa pistol-grip style endoscopic forceps 10 shown in FIG. 1A. Forceps 10includes a housing 20, a handle assembly 30, a rotating assembly 80, atrigger assembly 70 and an end effector assembly 100 that mutuallycooperate to grasp, seal and divide tubular vessels and vascular tissue.For the purposes herein, forceps 10 will be described generally,however, the various particular aspects of this particular forceps aredetailed in commonly owned U.S. Pat. No. 7,083,618.

Forceps 10 also includes a shaft 12 that has a distal end 16 dimensionedto mechanically engage the end effector assembly 100 and a proximal end14 that mechanically engages the housing 20 through rotating assembly80. As will be discussed in more detail below, the end effector assembly100 includes a monocoque jaw design. The term monocoque as used hereinis defined as a structure in which the outer skin or shell carries allor most of the torsional and bending stresses, or a structure in whichthe body is integral with and shares the stresses with the chassis.

Forceps 10 also includes an electrosurgical cable 310 that connects theforceps 10 to a source of electrosurgical energy, e.g., a generator (notshown). The generator includes various safety and performance featuresincluding isolated output, independent activation of accessories, andInstant Response™ technology (a proprietary technology of Valleylab,Inc., a division of Tyco Healthcare Group, LP) that provides an advancedfeedback system to sense changes in tissue many times per second andadjust voltage and current to maintain appropriate power. Cable 310 isinternally divided into a series of cable leads (not shown) that eachtransmit electrosurgical energy through their respective feed pathsthrough the forceps 10 to the end effector assembly 100.

Handle assembly 30 includes handles 40 and 50; handle 40 is movablerelative to handle 50 from a first spaced apart position wherein the endeffector assembly 100 is disposed in an open position to a secondposition wherein the end effector assembly 100 is positioned to engagetissue. Rotating assembly 80 is operatively associated with the housing20 and is rotatable in either direction about a longitudinal axis “A”.Details of the handle assembly 30 and rotating assembly 80 are describedin the above-referenced patent, namely, U.S. Pat. No. 7,083,618.

FIG. 1B shows a so called “in-line” endoscopic forceps 10′ for use withvarious surgical procedures and generally includes similar elements asdescribed above (e.g., handle assembly 30′, housing 20′, rotatingassembly 80′, trigger assembly 70′, shaft 12′ and end effector assembly100′) that, together, mechanically cooperate to impart movement of thejaw members 110′ and 120′ from an open position wherein the jaw members110′ and 120′ are disposed in spaced relation relative to one another,to a clamping or closed position wherein the jaw members 110′ and 120′cooperate to grasp tissue (not shown) therebetween. Handle assembly 30′includes two opposing handles 30 a and 30 b that are each movablerelative to housing 20′ from a first spaced apart position wherein theend effector assembly 100′ is disposed in an open position to a secondposition closer to housing 20′ wherein the end effector assembly 100′ ispositioned to engage tissue. Rotating assembly 80′ is operativelyassociated with the housing 20′ and is rotatable in either directionabout a longitudinal axis “A”. The various particular aspects of thisparticular forceps are detailed in commonly owned U.S. patentapplication Ser. No. 11/540,335.

For the purposes herein, forceps 10 is discussed in further detail withrespect to the monocoque jaw assembly of the present disclosure;however, it is envisioned that either endoscopic forceps 10 or 10′ mayinclude the presently disclosed jaw design.

As mentioned above, and as shown best in FIGS. 2A and 2B, end effectorassembly 100 is attached at the distal end 16 of shaft 12 and includes apair of opposing jaw members 110 and 120. Movable handle 40 of handleassembly 30 is ultimately connected to a drive assembly (not shown)that, together, mechanically cooperate to impart movement to a drive pin170 which, in turn, cams the jaw members 110 and 120 about pivot 160from an open position wherein the jaw members 110 and 120 are disposedin spaced relation relative to one another, to a clamping or closedposition wherein the jaw members 110 and 120 cooperate to grasp tissuetherebetween. Other suitable methods of closing and/or opening jawmembers are contemplated in the art such as reciprocating closure tubeassemblies, gear mechanisms, camming mechanisms, rack and pinionsystems, pulley systems, etc.

Turning now to the figures, FIGS. 3-6, the present disclosure describesvarious embodiments of a monocoque jaw design and methods formanufacturing the same. More particularly, FIGS. 3 and 5 show oneembodiment of a monocoque jaw member 110 that includes an electricallyconductive or sealing plate 112, a support member 114, an insulativecover 116, and a filler material 118 that could be conductive orinsulative, depending upon a particular or desired configuration. Inthis instance, jaw member 120 includes similar elements (e.g.,conductive seal plate 122, insulative housing 126) as described abovewith respect to jaw member 110 and as further described below. Afterassembly of each monocoque jaw member, the two jaw members 110 and 120are then assembled to move about a common pivot, e.g., pivot 160 asdescribed above with respect to FIGS. 1A-2B.

Support member 114 may be constructed from any suitable metalcontemplated in the art and may be stamped or otherwise formed toinclude a generally U-shaped configuration with an outer surface 114 aand two downwardly depending sides 125 a and 125 b. The support member114 may also be stamped in various other shaped configurations, forexample, an substantially V-shaped configuration, a substantiallyO-shaped configuration, or any other suitable shaped configuration.

In another embodiment a pair of flanges 132 a and 132 b extend outwardlyfrom the free ends of sides 125 a and 125 b, respectively, and areconfigured to run along the length of support member 114 creating aperipheral lip. The U-shaped support member 114 thereby defines an innercavity 130 configured to receive the filler material 118 as described inmore detail below.

Insulative cover 116 is configured to encapsulate support member 114 andmay be formed from any suitable material, such as plastic, epoxy, resin,gel, polymer-based materials, so-called cool polymers, etc. Cover 116may be mechanically engaged atop support member 114, may be formed in adie plate, or injection molded as part of a manufacturing step so longas insulative cover 116 protects surrounding tissue from electricalcurrents. More particularly, cover 116 (when formed) includes an innersurface 119 having two depending side surfaces 136 a and 136 b whichtogether define a cavity 117 that is configured to encapsulate supportmember 114. Again, the inner surface 119 and sides 136 a and 136 b maybe pre-formed in a die plate or injection molded to encapsulate thesupport member 114.

As mentioned above, jaw member 110 also includes a seal plate 112 and anfiller material 118 disposed between the seal plate 112 and the supportmember 114. More particularly, the filler material 118 is configured tofit inside the cavity 130, which may be pre-formed in a die plate orinjection molded into the support member 114. Filler material 118 may beformed from the same insulative material as the cover 116.Alternatively, as mentioned above, the filler material 118 may beconductive and may be formed from any suitable conductive material. Forexample, filler material 118 may be electrically insulative, thermallyinsulative, semi-conductive, or conductive according to a particularsurgical purpose or to achieve a particular surgical result.

Upon assembly, the filler material 118 provides structural support forthe support member 114 during load conditions, and under certainconditions may be adapted to thermally dissipate heat to facilitateconsistent tissue treatment. As mentioned above, insulative cover 116acts to insulate surrounding tissue, and under certain circumstances maybe adapted to dissipate heat or thermal spread to surrounding tissue.Support member 114 is designed to off-load or carry part of the loadduring high pressure applications, such as vessel sealing, and alsooffload the torsional and bending stresses associated therewith.

Support member 114 may be configured to engage sealing plate 112 bywelding, gluing, or other suitable engaging methods. For example, a weld135 may run along the edge of sealing plate flanges 132 a and 132 b tosecurely engage sealing plate 112 to support member 114, thus formingthe U-shaped monocoque jaw skeleton 155 (See FIG. 3). Filler material118 is configured to be placed between inner cavity 130 of supportmember 114, thus increasing structural strength of the jaw member 110and, in particular, providing rigidity to the sealing plate 112. Cover116 is then overmolded or limited to encapsulate the support member 114(and sealing plate 112/filler material 118 assembly) to electricallyinsulate surrounding tissue from the outer periphery of the jaw member110.

FIG. 4 shows another similar embodiment of a jaw member 210 thatincludes a sealing plate 212 having a knife slot 238 defined along alength thereof. Jaw member 210 includes similar elements and ismanufactured and assembled in a similar fashion as described above withrespect to jaw member 110. For example, jaw member 210 includes asealing plate 212, a filler material 218, a support member 214 and aninsulative cover 216, that are assembled to form monocoque jaw member210 with a knife channel 238 disposed therealong configured toreciprocate a knife (not shown) for cutting tissue. Filler material 218may also include a recess 218′ therein that is configured to accommodatea resulting bulge 212′ formed in the sealing plate 212 upon creation ofthe knife channel 238.

One of the sealing plates, e.g., seal plate 122 (See FIG. 2A) mayinclude one or more stop members 150 disposed on or operativelyassociated with the inner facing surface of the electrically conductivesealing surface 122 to facilitate gripping and manipulation of tissueand to define a gap “G” (not explicitly shown) between opposing jawmembers 110 and 120 during sealing and cutting of tissue. A series ofstop members 150 may be employed on one or both jaw members 110 and 120depending upon a particular purpose or to achieve a desired result. Adetailed discussion of these and other envisioned stop members 150, aswell as various manufacturing and assembling processes for attachingand/or affixing the stop members to the electrically conductive sealingsurfaces 112, 122 are described in commonly-assigned U.S. Pat. No.7,083,618.

FIG. 6 shows a flowchart that illustrates a method 500 for manufacturinga monocoque jaw member according to the present disclosure. Method 500includes step 502 of providing a seal plate 112 and a U-shaped supportmember 114 having flanges 132 a and 132 b which extend therefrom. Method500 further includes step 504 of attaching the sealing plate 112 to theflanges 132 a and 132 b along a length thereof to form a box-likesupport skeleton 155 having a cavity 130 defined therein. At step 506, afiller material 118 is injected into the cavity 130 to bolster thesupport member 114. As mentioned above, filler material 118 may alsoinsulate the inner cavity of the support member 114. Step 508 furtherincludes overmolding an outer periphery of the box-like support skeleton155 with an insulative cover 116.

The seal plate 212 of step 508 may be configured to include a knifechannel 238 defined therein and may include one or more stop members 150disposed therealong depending upon a particular surgical purpose. Step504, which includes attaching the sealing plate to the flanges along alength thereof to form a box-like support skeleton, may include welding,soldering, gluing and mechanically engaging (e.g., pinching, crimping,riveting, shrink forming, etc.).

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example, the cover 116 may be placed on support member114 by overmolding (covering) a material on an outer surface of thesupport member 114 as mentioned above or by placing a pre-fabricatedcover over support member 114. In addition, filler material 118 may alsobe pre-formed or pre-molded and inserted into cavity 130 to form thestructural support for sealing plate 112.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed:
 1. A jaw member for use with an electrosurgicalforceps, the jaw member comprising: a support member having a firstsurface and a pair of sides that depend therefrom defining a cavitytherein, a free end of the sides each including a flange that extendsoutwardly therefrom; a conductive plate adapted to connect to anelectrosurgical energy source and attached to bridge the flanges toenclose the support member to form a box-like skeleton; a fillermaterial disposed within the cavity; and an insulative cover disposedabout a periphery of the box-like skeleton to insulate surroundingtissue during activation of the conductive plate.
 2. The jaw memberaccording to claim 1, wherein at least one of the filler material andthe insulative cover includes at least one of a plastic, epoxy,polymer-based materials, resin, gel and combinations thereof.
 3. The jawmember according to claim 1, wherein the filler material and theinsulative cover are made from different insulative materials selectedfrom the group consisting of plastic, epoxy, resin, polymer-basedmaterials, and gel.
 4. The jaw member according to claim 1, wherein theconductive plate includes a knife slot defined therein.
 5. The jawmember according to claim 1, wherein the support member is stamped toform a substantially U-shaped configuration.
 6. The jaw member accordingto claim 1, wherein the insulative cover is an overmold.
 7. The jawmember according to claim 1, wherein the insulative cover is a coating.8. The jaw member according to claim 1, wherein the conductive plate isattached to the support member to form the box-like skeleton by at leastone of welding, soldering, gluing, and mechanically engaging.